The main idea is a species of giant crabs that have various ecosystems of lifeforms inside their shells instead of internal organs. Some of these crabs have civilizations inside them. This is a very early work in progress. I would love to work on it with your feedback and even collaboration.

Very interesting! Obviously, one of the first things you should do is to add in the containment procedures. You need those. Also, you should fill in all of the subsections and all of that jazz before you submit it for feedback. One more nitpick: when you aren't listing a specific measurement, you should write out "km" as "kilometers". Keep up the good work, I can't wait to see where this goes!